This invention relates to a clean release postal card or mailer and a continuous form for preparing a series of postal cards or mailers, and in particular to a construction in which a releasable adhesive secures together a base sheet and a cover sheet which obscures confidential information printed on the base sheet until opened by the addressee. The base sheet can be imaged through the use of chemical carbonless techniques.
Many types of confidential information are transmitted through the mails in the form of messages, invoices, notices of bank account balances and/or interest income for tax purposes, and the like. Previously, where information was desired to remain hidden until received by the addressee, envelopes were used. Post cards, on the other hand, are useful for delivering short messages, are less expensive to mail, and are relatively simple to be printed by automated equipment. However, post cards have not been suitable in the past for the delivery of confidential information because the printed message was easily read by persons other than the addressee.
More recently, attempts have been made to produce post card constructions which permit the obscuring of confidential information until receipt by the addressee. For example, Tanaka, U.S. Pat. No. 4,278,199, teaches a post card construction in which confidential information is preprinted on the card, and then an opaque cover member which is substantially smaller in size than the card is adhered to the card, covering the confidential information. In one disclosed embodiment, Tanaka teaches adhering the cover member, as well as means for transferring impressions entered on the cover member, such as a sheet of carbon paper or a carbon spot, to the card prior to printing, and then imprinting the confidential information through the cover member to the card.
Shishido, U.S. Pat. No. 4,742,954, also teaches a post card construction in which preprinted confidential information may be hidden from view by a laminated cover sheet which is secured to a transparent protection film layer bonded to a base sheet. The cover sheet is delaminated from the base sheet by the addressee of the post card to reveal the confidential information.
However, both Shishido and Tanaka suffer from shortcomings which render them as less than perfect solutions to the long-standing problem of finding a simple postal card construction capable of containing hidden confidential information. The laminate construction of Shishido requires the interposition of both a clear protection film and a coupling layer between the cover member and base sheet. This coupling layer must be laminated by a heating operation within a closely controlled temperature range. Further, Shishido appears to require at least two separate printing operations, once to print the confidential information on the base sheet and again to provide addressee information on the top of the cover member.
Tanaka requires the careful placement of a small cover over preprinted confidential information. In an alternative embodiment, the cover and a separate sheet of an impression transfer means must be correctly positioned over an area to be printed. Additionally, the adhesive of Tanaka is permanent, requiring the additional operations of providing perforations or tear strips in order for the recipient of the card to be able to readily remove the cover member. Further, neither Shishido nor Tanaka describe a procedure for automating the production of a series of postal cards.
Accordingly, the need still exists in the art for a simple post card or mailer construction which is capable of providing hidden confidential information to an addressee. Further, there remains a need for such a construction which can be used in an automated system for the production of a series of such postal cards or mailers.